The modern athletic shoe is a combination of many elements which have specific functions, all of which must work together for the support and protection of the foot during an athletic event. Cleated athletic shoes, particularly soccer shoes, typically include a sole having an upper extending upwardly from the sole and into which the foot of the athlete is positioned and secured in place. The sole provides traction, protection, and a durable wear surface. In addition, a plurality of cleats are secured to the sole and extend downwardly from it to provide the traction of the shoe when the athlete runs on a ground surface. The design of athletic shoes has rapidly become a refined science. However, the advancement of that science as to cleated footwear has in some ways been less rapid and less developed.
The sport of soccer imposes special demands upon player footwear. In the modern game, players run increasingly long distances. In a 90 minute match, a player may run as much as (or more than) 14 kilometers (over 8.5 miles). When practice sessions are also considered, a player may run in excess of 70 kilometers (43.5 miles) per week while wearing soccer shoes. It is thus important that soccer shoes be as comfortable as possible.
The presence of cleats on the shoe sole presents additional problems in this regard. Specifically, cleats can cause point pressures on a player's foot, particularly when the player is running over a frozen playing field or other hard surface. Moreover, the relatively long distances that a player must run, in combination with the side-to-side motions, foot-planting motions (for kicking a ball) and other common motions, can cause a player to become even more fatigued and injury prone than the player might be from running alone.
Significant advances have been made in the design of a cleated athletic shoe for the game of soccer. Commonly-owned U.S. patent application Ser. No. 10/179,013 (titled Article of Footwear Having a Regional Cleat Configuration) describes different cleat designs for the lateral and medial portions of the shoe (particularly the sole) in order to enhance flexibility, balance control, propulsion, stability and support in the specific areas where needed. Commonly-owned U.S. patent application Ser. No. 10/179,014 (titled Article of Footwear Having Medial and Lateral Sides with Differing Properties) also describes varying cleat designs for the medial and lateral regions in order to improve performance. However, further advantages can be achieved.
Pronation, or the rolling of a foot from the outside to the inside during running, is of special interest. In particular, pronation occurs as a runner's foot strikes the ground on the outside (or lateral) edge of the foot and the foot then rolls inward so as to place the inner (or medial) edge on the ground. A certain amount of pronation is natural and necessary for normal running. However, excessive pronation can lead to fatigue and injuries.